Internal combustion engine



July 26, 1938- w. B. BIDWELL. 2D

' INTERNAL coMBusTIoN ENGINE f original Filed oct. 25, 1935 5 Smeets-Sheet`V 1 July26, 1938.'l w. B. BIDWELL. 2D 2,124,604, f I INTERNAL COMBUSTIQNE NGINE y original Filed oct.' 25, 19?;5 l s AsrngfS-,sneet 2 L vll/1111111 @mmv Mig N f'l-f-M INTERNAL COMBUSTIN ENGINE original Filedoct. 25, 195s s s':seats-sneet-K1sY f l Patented July Z6, 1938 r Y i i l o y o I kUNITED STAT-Es PATENT'oFFlcr.

`INTERNAL ooMBUs'rloN ENGINE 'william B. Bidwell, II, Portland; oreg., :asignar` ofi-one-half to William C. BidwelLPortland,

applicati@ oetpber y25, i935, serial No. N46,696

Renewed June ,13, 193

6 Claims. (01.174-551 My invention relates to internal combustion Fig. is a section inplan of my Aenginewhich engines in which a three lobed cam is used by way shows a multiple of the' series of power units illus-` of a reducing mechanism, to utilize the eftrated in the first four `figures andA for convenciency normally characteristic of high piston ient reference may be considered taken on 'the 5 speeds in internal combustion engines,'with a line 5-5 of Fig. 1. if l f power take-off shaft having a less speed, in this' Fig. 6 is vadiagramm'atic representation ofthe case one-third, which amounts in eifectto arelower bank of engines thatwillbe directly underducing motion without the disadvantages inhervn'eath those shown in 5. The purpose of this ent in gear andpinion structureathe advantages view is t'o show the relative *positions* of the op- 10 of which havev been visualizedfora long time, erating units of the lower bank assuming that l0 but which, so far as I am aware, havev never the upperjbank units a'rein the'position shown been 'successfully realized notwithstanding a in Fig. 5;

number of patented embodiments r'of different Fig. 7 is a diagrammatic` representation of the forms, vwhich 'proved impractic'able, principally power moments of the 12 cylinder engine shown l5 von account of localized high thrust moments.' in Figs. 5 and 6 as viewed from a 45 degree angle, lil f One of the obstacles to successful application hereinafter explained in detail. t of this principle, hitherto regarded as insur- Fig. 8 shows a firing cycle `ofthe structure mountable, hasv been the apparent necessity of shown in Fig. 1 and will be characteristic of placing the thrust due to the combustion of fuel each set of four engine units of a. group Toom-f y at some point beyondthe open end of the engine prising a complete engine unit. 'I'he -purpose of 20` cylinder, thus'placing an unsupportable angular this view isto illustrate thatwhen each engine thrust moment on `the piston with respect to the resan. engine Opposite t0 it is always in 0m' walls of the cylinder. i pression. Hence the power ofthe flringunit'is One of the objects of my invention isfto overpartly used in compression,y and vpartly applied come this by a novel construction, hereinafter tothe turning moment of the shaft through the 125 more completely set forthin detail. cam, and the energy required to compress thef@ Another object ofvmy invention is to so place opposed unit to firing position is not transmitted the axis of the engine shaft or `cal'n shaft with through the shaft or cam. g i

respect to vthethrust of the pistons on firing Fig. 9 is'an enlarged view of the centralpor. i

stroke that in effect the engine is always ywell tion of Fig. 1 with the two ends broken awayandV` 30 f past center when the firing impulse reachesv th with a. broken opening through the cam to show l cam as a moment of revolution. Y the necessary construction of the crosshead-'with The forces of greatest magnitude in an inrelation to the shaft. ternal combustion engine are, first f the 4power Fig.10 is a Vsection on the line Ill-I0 of Fig. 9.

stroke and, second the compression stroke which Fig. 1'1 is'an enlarged view o f one end 0f the 35` is of opposite character and must be subtracted cro'sshead 'with a portion of the cam'in prperrei from the `power stroke before net power is availlaticnship; and with the articulation arms mountableto perform useful work. i ed'thereon. This figure shows thearcuate surface e Another object of my invention vis to deliver ofthe camvat the point of contact offthec'am f 40 only the net power'to the shaft, as will be hereinroller required by the arc at the terminusl of the -40 N after explained, thus decreasing thrust and bear` 'directly opposite lobe of the cani as hereinafter ing loads on the power shaft, bending moments pointed out. 'i l t' on the 'shaft proper and, indirectly, stresses set Fig.'12 is an Orthographie projection of. Fig. 511'.V up in engine framestructures. n Fig. 13 is a view of the crosshead detached from l Accomplishing theseand` other objects that will the structure'shown vin Fig. 9. f 45",

i be apparent from thespecication anddrawings These drawings delineate three, four cylinder herewith, which will be clear to those to `whom engines arranged tov deliver `power to 'a `common f this specification isaddressed, is the purpose of shaft, the three cams being spaced aroun'dthe the present invention.r i l shaftV to equalize power delivery. Consideringk In the drawings,- y. the drawings, Figs. 1 to'4 inclusive, thezpower 5o Figsl, 2, Band 4 are transverse sections of shaft 20 'has a three lobed cam 2|,1made rigid my Lnew engine taken on `the lirie I-I of Fig. 5 therewith. A cam case122, isprovided'with suite and rshowing four differentpositions of `the en'- able bearings 23, (Fig. 25)', S0 `that the'shaft' 20;' Y* gine to illustrate cycles of operation as will be` is rotatable within the cam'case. gv y 55 hereinafter'more completely described in detail. rMounted at opposite ends of the cam case 22, l55

are cylinder blocks 26 and 25, diagrammatically l shown to be provided with valve gear, whichwill not be further described since it does not form a part of the invention tobeclaimed in this apy plication.l

Pistons a and'b are movably varranged in the cylinderiblock' 24; andy pistons c andy d are movably arrangedzin.. the known manner withiny the cylinder block 25. l

.A crosshead v2li, is provided with two cam' rollers 21 and 28 mounted for-revolution uponA `the bearingsl 21a and 28a and'so spacedthat they will bein running contact with the cam 2| ,at all `points during a complete revolution of 'the' cam,y

' j To further'insure against thrust momentsr appeering in 3 |destructive magnitude on the piston cylinder surfaces, articulation arms (all being 'given the "same numerical designation because they are identical) are pivotally attached to the crosshead at 'and tothe piston pin'32 (seeFig. 1). fThis is kan .importantv item of. construction in thisrtype o f engine .for the 'reason that when operating temperatures are attained the distance from center to centerof cylindersk at anyilring `end.will bevdiiferent by some thousandths of an ',inchthan whenthe engine is at non-operating uniformtemperattire.v Hence without theprovi- `sion of the varticulation arms 30 a veryheavy thrust load wouldappear between thelpistons and their cylinder walls; butfwithy thisv construction I' practically the konly load A'will be that Yofv v. the ,springiness of thewellknown piston ringwhichv is understood to be present.

f hintended to be used herein but which lhas not `beenwshown in thesevdr'awings since they will be As is well'known toV those Yfvwainiliar .the

y, `design of internal combustion engines,the forces oi'greatest magnitudewhich must be controlled `end utilized are iirstgthose of/the power stroke ofjther engine, and second,` the power required'fjor compression just before the power stroke begins. By the novelarrangement of my engines, each cylinder and piston. being considered anengine,

. vI amiable -to subtractthe power requiredl for a compression stroke from an engine delivering a power stroke ,and deliver the yremainder to the powerfdelivering part such as a shaftg'without being'compelled to iirst impress the power into the Ashaftfentailing heavier bearing l'oadszand other disadvantageous moments, andthen'take it` i oi again to use/ for compressing-aV charge of air rig. l1.

vpower stroke designated`by"iire.y in `Fig. 8; enf

ingfanother engine.;vv

yThis is vexplainedy comparing 8 with Engine "'b. will be Vabout to `deliver'its .gine;fd will make its compressionfstroke simul- V taneously lwith the power'stroke of Aengine'fb intake strokes) (engine. c..being von, exhaust and` engine "a on Thus itk isA clear that the power required `rfor-v compression in' engine dffis deliveredon a straight line-from engine ffb. through the crosshead as indicated by 'the straight line and does not inuencethe shaft 2|) which -imerely receives the surplus through kthey cam 2 pression and engine kc on its intake stroke.

Engine b having completed the delivery of its power stroke and engine a" having completed its intake stroke simultaneously, engine 12" 1s then ready to fire while engine a will be incom- The power required to compress engine a willthen bedelivered along the: line d'a at small angle with respect to the crossheads', and very effective as to theapplication of thrust and resistance.

When engine a fires the compression of engine c will beapplied along the line :1w-c, again a straight line` like, b-d, and when engine fc nres the transmission of power to compress engine b is applied along the line c b, which is an angle similar tothe line d-a,` and thus itis seenfthat foreach completed cycle one-half of the-'thrusts absorbed by compression are `in a Vdirect line and the other` half are at a low angle.

By observing the position of the cam 2| when adiagonal thrust is beingdelivered it. wi1l' be apparent that the angularity ofthe thrustis in all cases taken by the camfand translated' into l turning moment'instead of` appearing yas load at .the crosshead slipping surfaces. 'Y

- t An important feature ofmy newengine is that the terminus of each lobe of the .cam 2|k is a 1 short arc having the center of thecam as its center ofv radius and that a corresponding arcuate portion is placed opposite each'lobe terminus inthe throat between lobes.

several pounds per sq. inch of supercharging n pressure is employed.4 l l v ,d

It is intendedtto use superchargers with :rny'newv engine but thefactthat my engines come to a 30 This engine is intended to run atmextremely .high piston speedA and the inertia of the air normallyv prevents iilling thecylinders on th'elnld take stroke with air at suitable density 'unlessfull stop for approximately ndegrees of `revrolul:

tion of the lcamv 2|, at the lendv of each's'troke .whether into or out'of the cylinder, enables me f to get a. substantially higher atmospheric tension .within the .cylinder underfany'conditions thanr can be obtainedwithout it., .f

VThis has been illustrated linthe ldrawings iFigs. -1 to 4 inclusiveginy-which thev camg 2| is shown in allof the'gures withlits relation to theengine whatit will be when the ring or dotted outlines showing rthe position that the cammust move to,` beiore the powerstroke begins to.l be effective.

With the engines in, this position it will-be grecs before the ring' stroke kcan" become eiiec'- `power Vstroke v actually commences, and with 1.

`understood that the camhas alreadyadvanced about 21/2 degrees.- with the engines at-irestfand that yit. will haveto advance another21/2=de tive'. This latter improves flamepropagation in .i

ditional time to llthe yengine that is 'complet'- ing'its `suction stroke. Obviously scavenging will also beimproved.

v the engine'that is nrin'g'an'd isfutiliza as-ad- The purpose of Figures Y10' tjof l13 in ziusivfel is iif lustrati'ngd.theV adaptability of Y the vdesign to attain minimum, reciprocating weights-.so essential :with highpiston speeds.YV .The articulation arms are quite short, hence maybe skeletonizred as shown in Figfll or made with la Vtl1i n web as shown'in Fig. l13vand willv carry the greaterf-part `of the power developed by the engine units" directlytothe cam through the close coupled cam 'Y roller.v The crosshead proper can be skeletonv ized, even morel than` shown, with safetysince its duties reachtheirA maximuxn`- when carrying;M fr

the compression load of a piston ing position.

The engine, as shown in Fig. 1, lends itself readily to multiple construction, Fig. 5, with a practically continuous power shown in Fig'. 7.

reaching fir- Fig. 7 is a diagrammatic plot showing the flring order of the twelve cylinder motor indicated by Figs. 5 and 6 composed of three rectangular groups like Fig. 1 and its purpose is to illustrate' the practically continuous ilow of power possible as virtue of the novel arrangement of yengine units shown inFigs. 1 to 4 inclusive, to be realized when as many as three of such units are arranged as indicated. There are one and a half vpower impulses delivered by each piston-cylinder unit per revolution of the cam inthe cycle assem-` bly shown. I

In the diagram the near upper bank of engine j units, Fig. 5, are indicated by the letters a and c which agree with the indices used in Fig. 1.

The other top units are indicated by a2, a3, c2`

and c3 respectively. t t

'I'he near bottom units are yindicated by the letters b and d to agree with the designation given in Fig. l and with`numerical suixes b2, b3 and d2 and d3 vrespectively to indicate other bottom units. l

The firing order is indicated by the legends in Fig. 7, it being obvious vthat in thev position j shown b fires first and d will follow, but between them c3 will ilre and so forth. Obviously the ring order may be changed but itis notbelieved to be advantageous to depart from the system shown.

The overlap of power impulses gives a practically flat power curve' and the opposition of impulses relieves the cam shaft of bending moments to a very remarkabletdegree,y particularly when it is remembered that the compression stroke of a given unit is achieved by almost straight line power`from an opposed-unit andv .what may be calledV the back side of the cam lobe, the surface indicatedv by numeral 50, Fig. 1, does no work.

Having disclosed myvinvention so"that those" familiar with, the art to which it appertains-may makeand use it, what I claim as new and desire to secure. by Letters Patent, is,-

1. An internal combustion engine of the singlev cam typel comprising two pairs of Opposed engine units, the axes of said pairs being parallel, and

` ilow pattern as of the transverse axis oi the cam.' a guided cross'- head, and articulated connections between the engine units and the cross head. i;

2. An internal combustion engine of the single cam and crosshead type comprising two pairs of opposedengine units, in parallel relationship,A the axes of said pairs being equidistantly spaced from a line drawn at right angles to the axis vof revolu' tion of the cam, andarticulated connections between the engine units and the crosshead.

3. A combustion engine comprising four engine units arranged in rectangular -form with opposed j pairsof engine units spaced apart in the same. plane, a single cam mounted forirevolution ceni-r-l trally of the rectangle, a crosshead reciprocably` movable with respect rto the cam, articulated connecting means between the engine units and the crosshead and a thrust roller spaced between the y' l t axes of the engines at each end of the crosshead for translating reciprocating motion of the crosshead into moments of revolution of the cam.

4. In an internal combustion engine of the v characterdescribed, two vpairs of opposed recip-r rocating vengine units inspaced relationshipY in the same plane, a single cam mounted for revolution withr its axis spaced between the axes ofthe'k p engine units and normal thereto and crosshead with articulated connecting rod means for changing the reciprocating motion of said engine units to moments of revolution of said cam.

5. A four cylinder internal combustion engine* comprising an engine case, a multilobedscam` I mounted for revolution in said case, a substantially rectangular crosshead reciprocably mount'-v ed with respect to the cam, a thrust roller mounty ed at each end of the crosshead for cam contact@ on aline normal to the axis thereofv and. engine pistons articulated to each of the four c'ornersofV V the crosshead.

6. A `four cylinder internal combustion engine comprising a cam case, a cam mounted for revolu` tion in the case, a pair of engines in side by sideL and pivoted connecting and the crosshead. 

